ref #511

If name N is required, and all providers of A also provide B, it
means that only instances of B can be selected that provide N. This
is strong help with cases when so:libfoo.so.1 is updated to
so:libfoo.so.2 and not everything is recompiled.

Otherwise we cannot override with --no-progress

- let the apk_print functions deal with the forced print itself. We
  avoid that the callbacks need to deal with the force flag. We can
  also get rid of the APK_PRINT_PROGRESS_* defines.

- let the reader of --progress-fd decide how often things are updated
  rather than having a fixed granularity off 1/100 (percent)

- avoid detect screen size and percent/bar calculations in case the
  --no-progress was given

- track satistics for both the ascii bar and percent info and update bar
  only if either percent or bar changes. This makes the bar go smoother
  when width is wider than 100 chars and it makes the percent counter
  go smooth when screen width is less thann 100 chars. It also
  simplifies the callbacks as they no longer need to deal with update
  granularity.

With commit 0a131418 the percent
variable became an integer instead of size_t. We fix the format
modifier accordingly.

to consider only installed packages

Select latest version of package (if it is not pinned), and print
error if it cannot be installed due to other dependencies.

Together with --available, it selects the latest package which is
present at least in some repository.

This also fixes few solver issues with ordering of package selection
that got quite apparent with this flag. Namely, we cannot "lock"
a package until it's reverse dependencies are locked or not all of
the solver flags are propagated properly.

the pinning11 changed when @repo got the leading @ on error messages.
analyze_dep() now properly ignores conflict dependencies, as those
names are usually intentionally left unassigned.

to show different versions of package and the repositories from
which it is available from.

ref #511

if all packages named N provide the virtual package, list only the
name N instead of all packages providing it.

no need to muldiv all the time, just pass the current amount of bytes
done, and let callbacks use that directly.

instead use prefix for temporary files.

Fixes also 'fetch' applet to prefer copying/linking to files from
cache if possible.

So same package it is possible to not match same package multiple
times. Use generation count, so this is handled cleanly during
recursion, like in the use case of search applet.

and remove the now unused apk_dep_is_materialized_or_provided
which was superceded by apk_dep_analyze.

and add the provided version information to the conflicts.
fixes the final test case that was broken. hooray.

use the new apk_pkg_foreach_reverse_dependency helper to find
the reverse dependencies properly.

... in the error printing and the package deletion.

Instead of the dependency oriented logic, switch to print them
for each package or name needed. Might give a bit more readable
errors now. There's still few corner cases that proper error is
not output, which are cought by the test cases.

mostly useful for reboot, when all packages are not available.

- try harder to not change anything during self-upgrade
- also honor locking to packages that where earlier used in
  merging common dependencies
- clarify upgrade applet help messages

Fix also pinning test cases to be more sane.

Handle properly per-name preference flags, and add test cases
for testing those via fix applet.